Exhaust muffler for internal-combustion engines



Nov. 10, 1925. 1,560,947

. D. M. SKELTON EXHAUST MUFFLER FOR INTERNAL COMBUSTION ENG INES Filed April 28, 1921 Patented N... 10, 1 925.

' UNITED STATES 1,560,947 PATENT OFFICE.

DOROTHY I. SKEL'ION, 01' L03 ANGELES, CALIFOBNIA, ASSIGNOR TO WILLIS A.

' SKELTON, OF LOS ANGELES, CALIFORNIA.

EXHAUST MUFFLER FOR INTERNAL-COMBUSTION ENGINES.

Application filed April 28, 1921. Serial No. 465,146.

To all whom it may concern:

Be it known that I, Dono'rrn' M. SKELTON,

a citizen-of the United States, residing at Los Angeles, in the county of Los Angeles 5 and State of California, haveinvented a new and useful Exhaust Mufiler for Internal-Combustion Engines, of which the following is a specification.

My invention relates to devices used in connection with the exhaust pipes of internal combustion engines for the purpose of regulating the outflow of the combustion gases and thereby mufiling the sounds caused thereby.

The type of mufilers now in common use consist chiefly of receiving chambers having baflie plates situated therein through which the exhaust gases must pass before being delivered into the air. It is a conceded fact that such mu'filers create a back pressure which has the result of considerably reducing the effective power of the engine and also causes an unnecessary overheating of the motor cylinders, and it is for this reason that mufiiers are not used on aeroplane driving motors.

The principal object of my invention is to provide a mufller which will allow the free passage of the exhaust gases into the open air, and which will be free of back pressure creating elements, thereby allowing the motor in connection with which it is employed to operate at ,its highest efiiciency.

Other objects and advantages will a pear hereinafter from the following descrlption and drawings.

Referring to the drawings which are for illustrative purposes only,

Fig. 1 is an elevation of an automobile 40 shown a mufller embodying my invention in application thereto.

' Fig. 2 is a longitudmal section through the mufller shown in Fig. 1.

Fig. 3 is a front view of the mufiier.

The sound, or report, accompanying the emission of combustion gases into the open air is caused by these gases being delivered into the air in the form of impulses which cause sound vibrations to be set up. The ejection of a body of gas into the air compresses the air into which it enters and creates an initial oscillation in the air formation, and, due to its forward momentum, a vacuum is created before the mouth of the pipe from which it has been discharged.

The discontinuance of the pressure upon the air by the exhaust impulse allows the air acted upon to return to its normal state, and

to fill the vacuum'created by the outrushing exhaust gases, thusa return oscillation is produced in the air formation and a complete sound vibration results.

In'my nrufiler the exhaust gases are combined with a flow of air and are delivered therewith into the open'air in a continuous stream, thereby acting upon the air into which it is discharged in a continuous manner so that no strong vibrations are set up.

In the form of my invention shown in the drawings, the mufiler 11 is attached to the exhaust pipe 12 by a union coupling 13. The exhaustgases are received from the exhaust pipe 12 by a delivery pipe and are delivered thereby through the curved portion 21 of the pipe 20 into a discharge pipe 25. Inserted in that portion 26 of the discharge pipe which extends rearwardly from the point of connection 27 of the delivery pipe 20 to the discharge pipe 25 is a nozzle 30 comprised essentially of a converging nose 31 extending from a cylindrical formation 32.

Within the cylindrical portion 32 of the nozzle 30 is provided a check valve formed of a flat closure late 51 hinged at 52 to a sleeve 53. The p ate 51 is kept normally closed by gravity, and assumes the position indicated by the dotted lines 55 upon the passage of air therethrough in a forward direction. In order that the muffier 11 may be installed in positions other than that shown in the drawings, I make the check valve turnable within the nozzle 30 so that the covering means 51 may be suspended from the top as shown. I secure the valve structure in place by a set screw so that it may be ad usted in position to conform with the installation.

Enlarging rearwardly from the cylindrical portion 32 of the nozzle 30 is a collector funnel 33 which in passing through the air causes a flow of" air through the nozzle 30 as indicated by the arrows in Fig. 2. In order that the mufller 11 may be compact in construction, I pass the delivery ipe 20 through a sleeve 40 located within t e confines of the funnel 33.

The exhaust impulses in being delivered through the pipe 20 into the discharge pipe 25 pass across the opening 45 provided in ence of vibration causing conditions. The

flow of air induced by the passage of the exhaust by theopening 45 of thenozzle 30 is greatly assisted by the pressure created inthe funnel 33 due to its passage through the air.

I have shown and described my invention in use with an automobile, and, alt-hough'it is particularly adapted to this use, the muffler is equally eflicient where used in connection with internal combusion engines of all types, and especially aeroplane motors. It is to be understood that nozzles'of various sized openings maybe used without departing from the spirit of my invention.

I claim as my invention:

I 1. In a mufller the combination ofza dischargepipe; a delivery pipe to deliver exhaust gases from the motor into said discharge pipe; a nozzle in said discharge pipe through which a flow of air is interspersed between the impulses of exhaust gases by the passage of said exhaust gases across the mouth'of said nozzle; a check valve-located centrally within said nozzle for reventing a reverse flow therethrou h; an a collector to direct a flow of air iirough said nozzle, said delivery pipe extending through a sleeve in said collector.

2. In a mufiler, the combination of: a disin said nozzle; a collector to direct a flow of air through said nozzle; and a relatively movable sleeve in said air collector to support said check valve, said delivery pipe extending throu h a sleeve in said collector.

3. In a mu. er, the combination of: a discharge pipe; a delivery pipe to deliver exhaust gases from the motor into said discharge pipe; a nozzle in said discharge pipe through which a flow of air is interspersed between the impulses of exhaust gases by the passage of said exhaust gases across the mouth of said nozzle; a check valve located in said nozzle; a collector to direct a How of air through said nozzle; and a sleeve in said air collector to support said check valve, said sleeve being rotatably adjustable to suit the position in which said muffler is mounted, said delivery .pipeextending through a sleeve in said collector.

In testimon whereof, I have hereunto set my hand at s Angeles, California, this 22nd day of April, 1921.

DOROTHY M. SKELTON. 

